1. Field of the Invention
The present invention relates to a LED controlling driver and a controlling method thereof, and more particularly to a LED controlling driver, the controlling driver can control and drive the power levels or the blinking states of a light source comprises at least one light emitting diode, and a controlling method thereof.
2. Description of the Prior Art
Since Cavemen flared the first ray by fire in the remote antiquity, human beings have constantly pursued light in order to resist the darkness. In addition to the gas lamp, Edison invented an approach to use the new energy of electricity on October 1879, and further contributed to the birth of mercury light bulb. Following the advance of technology, human life become more convenient with invention of the LED, simultaneously, decreasing air pollution caused by lots of gas lamps and heavy-metal pollution by mercury light bulb; it is a great contribution to prevent the greenhouse effect and maintain the environment.
LEDs are special diodes. When a forward bias is applied, electrons and holes move in the semiconductor thin film and thus recombine with each other in the light-emitting layer due to the potential difference incurred from the external electrical field. At this time, part of the energy released by the recombination of the electron and hole pairs excites the luminescent molecules in the light-emitting layer to excited-state molecules. When the excited-state molecules fall back to the ground state, a certain portion of the energy is released in light form.
As technology progressing, LEDs emitting light of various colors (wavelengths) can be manufactured today. There are early-stage LEDs capable of emitting infrared rays or red light using gallium arsenide (GaAs) or aluminum gallium arsenide (AlGaAs). Besides, there are aluminum gallium phosphide (AlGaP) and gallium nitride (GaN) LEDs which emit green light and zinc selenide (ZnSe) and silicon carbide (SiC) LEDs which emit blue light, etc.
The luminous intensity (brightness) of an LED mainly depends upon the current going through the LED. The brightness is directly proportional to the current. Namely, higher brightness is obtained when a higher current passes through the LED, whereas the brightness is relatively lower when lower current passes through it. However, if a high current continues to be provided to the LED for the requirement of higher brightness, it will cause the problem of a decreased service life of the light emitting diode, high power consumption, or the like.
In order to solve the above-described problems, the prior art as shown in FIG. 1, which discloses a light emitting diode brightness control circuit 100. The light emitting diode brightness control circuit 100 is suitable for controlling the luminous brightness of multiple sets of light emitting diodes 130 used as a light source in a liquid crystal display. The light emitting diode brightness control circuit 100 comprises a brightness control pulse generation unit 110 and a plurality of light emitting diode direct current power supply units 121. The brightness control pulse generation unit 110 is used for receiving a brightness adjusting signal and generating multiple sets of brightness control pulse signals of the same frequency but with different phases based on the brightness adjusting signal. The duty cycles of the brightness control pulse signals change within a preset range based on the brightness adjusting signal. The light emitting diode direct current supply units are coupled to the brightness control pulse generation unit 110 to drive the corresponding light emitting diodes 130 based on the brightness control pulse signals.
However, the prior art still has the following problems to be overcome:
(1) Additional control circuits for controlling the brightness levels or the blinking states must be added so as to increase the cost. Thus, it is undesirable for indoor illumination due to its high price.
(2) Due to the lack of a detection-control module of the present invention, the power source cannot be operated by a user's switching operation so that the circuits cannot be driven to change the brightness level of the light source. Therefore, it is inconvenient in use.